This invention relates in general to hybrid drive systems and methods of installing such hybrid drive systems in vehicles and other mechanisms. In particular, this invention relates to an integrated hybrid drive module and to a method of installing and removing such an integrated hybrid drive module in a vehicle or other mechanism.
Drive train systems are widely used for generating power from a source and for transferring such power from the source to a driven mechanism. Frequently, the source generates rotational power, and such rotational power is transferred from the source of rotational power to a rotatably driven mechanism. For example, in most land vehicles in use today, an engine generates rotational power, and such rotational power is transferred from an output shaft of the engine through a driveshaft to an input shaft of an axle so as to rotatably drive the wheels of the vehicle.
In some vehicles and other mechanisms, a hybrid drive system is provided in conjunction with the drive train system for accumulating energy during braking of the rotatably driven mechanism and for using such accumulated energy to assist in subsequently rotatably driving the rotatably driven mechanism. To accomplish this, a typical hybrid drive system includes an energy storage device and a reversible energy transfer machine. The reversible energy transfer machine communicates with the energy storage device and is mechanically coupled to a portion of the drive train system. Typically, the hybrid drive system can be operated in either a retarding mode, a neutral mode, or a driving mode. In the retarding mode, the reversible energy transfer machine of the hybrid drive system accumulates energy by braking or otherwise retarding the rotatably driven mechanism of the drive train system and stores such energy in the energy storage device. In the neutral mode, the hybrid drive system is disconnected from the drive train system and, therefore, is substantially inoperative to exert any significant driving or retarding influence on the rotatably driven mechanism. In the driving mode, the reversible energy transfer machine of the hybrid drive system supplies the accumulated energy previously stored in the energy storage device to assist in subsequently rotatably driving the rotatably driven mechanism.
One commonly known hybrid drive system uses pressurized fluid as the actuating mechanism. In such a hydraulic hybrid drive system, a fluid energy storage device (such as an accumulator) and a reversible hydraulic machine are provided. Another commonly known hybrid drive system uses electricity as the actuating mechanism. In such an electric hybrid drive system, an electrical energy storage device (such as a battery) and a reversible electric machine are provided. Other hybrid drive systems are known in the art that use other actuating mechanisms.
Regardless of the specific actuating mechanism that is used, the hybrid drive system typically includes a variety of individual components. For example, a typical hydraulic hybrid drive system includes a plurality of hydraulic and pneumatic components, such as pumps, motors, accumulators, filters, and associated fluid conduits. In the past, these components have been installed on the vehicle or other mechanism in a piece-by-piece manner. Although this method of assembly has been effective, it has been found to be undesirable for several reasons. For example, in the context of the hydraulic hybrid drive system, such piece-by-piece assembly of the components of the hydraulic hybrid drive system often occurs in a relatively unclean environment. As a result, dirt and other contaminants can be unintentionally introduced into the hydraulic hybrid drive system, which can result undesirable maintenance time and expense. Additionally, such piece-by-piece assembly of the components of the hydraulic hybrid drive system prevents preliminary cleaning or testing of the entire system until after it has been fully installed within the vehicle or other mechanism. Lastly, the hydraulic hybrid drive system is often used in vehicles and other mechanisms having significant space and clearance restraints, thus causing installation (and subsequent removal if necessary) to be relatively difficult and time consuming. Accordingly, it would be desirable to provide an improved structure for a hybrid drive system and an improved method of installing and removing such a hybrid drive system in a vehicle or other mechanism.